Hi Brandon,
First, welcome to our forum - we are very happy to have you here. A request please?
No more ALL CAPS postings or titles. It is very hard to read and considered "shouting," believe or not, in internet manners.

It sounds like you are a very concerned and caring owner of your AST - excellent for you and lucky for him! The world needs more folks like you. His name is Riddick, is it?
Perhaps you could post some pictures of him and his problem areas?
I'm not a Vet and can't give you Vet advice, nor should you take it as Vet advice from anyone else here (we can't because we are not doctors nor have we seen Riddick).
But many of us have faced allergies in our dogs and can share our non-medlical experiences with you.
Allergies in dogs are a regular challenge and a real pain - both for us and our dogs.
Untreated they can lead to much more serious issues, infections, etc.
A few questions:
1) What are you feeding him right now and what have you tried before?
2) What kind of mites did the Vet say he had?
Over bathing can be an issue sometimes, but you said he had this issue before you adopted him, right?
Look at your home too. Are you using cleaning supplies on the floor or other areas he sleeps (even your bed if you allow it).
A classic issue is "contact dermatitis"
Contact dermatitis is a localized rash or irritation of the skin caused by contact with a foreign substance.
If he is sleeping on things like carpet scents (those powders you shake in before using the vacum) or other things like that it could cause contact dermatitis (so could many other issues).
So this is a start - there are other smarter folks around here who hopefully will add to this topic for you.
Craig
(publisher of DogExplorer)